Rock drill



ROCK DRILL S? mdk.

Oct. '1, 1935. M. c. HUFFMAN Filed Dec. 18, 1951 oct. 1, 1935. M HUFFMAN V 2,015,678

ROCK DRILL Filed Dec. 18, 1931 l 5 Sheets-Sheet 2A 4 i" A I a f .l5 5@ wat r Patented Oct. 1, 1935 UNITED STATES ROCK DRILL Mervin Chester Huffman, Claremont, N. H., asslgnor to Sullivan Machinery Company, a corporation of Massachusetts Application December 18, 1931, Serial No. 581,925

50 Claims.

This invention relates to rock drills and more particularly to improvements in feeding mechanisms for such drills.

An object of this invention is to provide an improved rock drill feeding mechanism. An-

other object is to provide improved controlling means for such a feeding mechanism. Yet another object is to provide an improved rock drill feeding mechanism of the pressure fluid actuated `type having incorporated therein improved means for regulating the feeding pressure. A further object is to provide an improved feeding mechanism of pressure fluid actuated type having associated therewith improved automatic feed 15 regulating means. These and other objects of this invention will, however, hereinafter more fully appear.

In the accompanying drawings there are shown for purposes of illustration two forms which the ,invention may assume in practice.

In these drawings:

Fig. l is a plan view of the illustrative embodiment of the improved feeding mechanism having mounted thereon a rock drill, parts being shown vin section to illustrate structural details.

Fig. 2 is a longitudinally extending vertical sectional view taken substantially on line 2 2 of Fig. 1, with parts omitted to facilitate illustration.

Fig. 3 is a longitudinally extending vertical sectional view taken on line 3 3 of Fig. 1.

Fig. 4 is a transverse vertical sectional view taken on line 4 4 of Fig. 1.

Fig. 5 is a transverse vertical sectional view taken on line 5 5 of Figs. 1 and 6.

Fig. 6 is'a vertical sectional view taken on line 6 5 of Fig. 5.

Fig. '7 is a vertical sectional View taken on line 1 1 of Fig. 5.

Fig. 8 is a detail sectional view taken on line 8 8 of Fig. 5 showing the manual feed control valve in a different position.

Fig. 9 is a detail sectional View showing the feed control valve in a still different position.

fic

*o lil-la of Fig. 9.

Figs. 11 and 12 are groups of detail sectional views illustrating the main throttle valve in various posi-tions of adjustment, each group show- 0 ing three valve positions, namely the neutral, forward feed and reverse feed positions, enclosed by a bracket. In the group shown in Fig. 11, the sectional views are taken in the plane of line 6 6 of Fig. 5, while the sectional views shown in Fig. 12 are taken on the plane of line 1 1 of Fig. 5.

Figs. 13, 14, 15 and 16, inclusive, are groups of detail sectional views illustrating the auxiliary control valve in various positions of adjustment,

60. each group comprising ve views; namely a, b,

Fig. 10 is a detail Sectional view taken on line c, d and e, enclosed by a bracket. In each group the views a, b, c, d, and e are sectional views-taken in the planes of lines c a, b b, c c, d d and e-e of Figs. 17, 18, 19 and 20.

Figs. 17, 18, 19 and 20 are side elevational views 5 showing the diiferent positions of the auxiliary control valve.

Fig. 21 is a view similar to Fig. 5 illustrating a modified form of construction.

Fig. 22 is a vertical sectional View taken on 10 line 22-22 of Fig. 21.

Fig. 23 is a vertical sectional view taken on line 23-23 of Fig. 21.

Figs. 24 and 25 are detail sectional views of the throttle valve shown in Figs. 22 Vand 23, with said 15 valve in altered position.

Fig. 26 is a detail sectional View of the feed control valve shown in Fig. 21 with the control valve in a different position.

Figs. 27 and 23 are detail sectional views of 20 the manual feed control valve shown in Figs. 22 and 23, showing the valve in altered position, and Fig. 2'7 being taken on the same plane but in opposite direction from Fig. 22, while Fig. 28 corresponds in View with Fig. 23.

Fig. 29 illustrates a still different position of the feed control valve.

Figs. 30 and 31 are sectional views taken onV lines Sil- 39 and 3l-3I respectively of Fig. 32.

Fig. 32 is a view similar to Fig. 26 showing an 30. intermediate position of thev feed control valve.

In both illustrative constructions the improved manual and automatic feed regulating means are shown embodied in a rock drill generally designated I, herein of the mounted drifter type, and are associated with feeding mechanism generally designated 2 of the same general character as that disclosed in my co-pending application Serial No. 415,695, filed Dec. 21, 1929,

now matured into Patent No. 1,955,744, patented 40 Apr. 24, 1934. It will be understood, however, that the improved feed regulating means may be embodied in drills and incorporated in feeding mechanisms of various other types.

In the present construction the rock drill I is of the pressure iiuid actuated hammer type having a usual hammer adapted to impart, in a well known manner, a series of impact blows to a usual drill steel 3. The actuating liuid for the hammer motor is supplied through a usual inlet connection 4 and controlled by a throttle valve mechanism 5 carried by the rear head 6 of the drill. The rear head 6, the ham mer cylinder 1 and the front chuck Vhousing 8 are held in assembled relation by usual spring tensioned side rods 9, 9 as is usual in rock drills of the type disclosed herein. As the particular construction of the rock drill is not of any importance in regard to the invention herein, a 6o'l boit-s ls.

description and illustration of the internal structure thereof is not requisite.

The feeding mechanism 2 consists of a reversible feeding motor including a pair of parallel feed cylinders I9 and II spaced transversely and supported upon a suitable bracket I2 carried bya saddle trunnion I3. The cylinders are rigidly secured to the bracket I2 in any suitable manner and the rear ends of the cylinders are held in rigid spaced relation by a transverse connecting member I4. The forward ends of the feed cylinders are connected by a transverse head member I5 carrying a centralizer or guide I5 of a suitable design for the drill steel 3. The rock drill is supported directly on and between the cylinders I,' II by the provision of a depending portion I1 which may be of suitable longitudinal length so as to provide Vsufficient bearing surface while a clamping element I3 is removably secured to and spaced from the portion I1 as by screw The elements I1 and I8 present arcuate bearing surfaces slidably engaging the inner portion of the periphery of the cylinders I9 and II. It will thus be seen that the rock drill is entirely supported by and slidable directly on the feed cylinders without the intermediation of any other elements thereby causing the feed cylinders to perform all the functions of both feeding elements and guiding elements. Reciprocably mounted in the feed cylinders I0 and II are feed pistons 20 and 2| respectively, having rearwardly extending piston rods 22 and 23 connected at their ends by a transverse connecting head 24. The rock drill is likewise connected to this head 24 by the provision of a rod 25 secured at 26 to the rear head 6 of the rock drill and threadedly connected at 21 within the connecting Vhead 24. Formed within this rod 25 and controlled by the valve mechanism 5, as hereinafter described, are forward and reverse feed passages 28 and 29, respectively; the former being connected through a passage 3 with a bore 3| formed in the piston rod- 22, While the latter passage is connected by a passage 32 with a bore 33 formed in the piston rod 23. The bore 3| is communicable, as shown in Fig. 3, through passages 34 with the feed cylinder bores at the rear sides of the feed pistons; the ends of the feed cylinder bores being connected by a transverse duct 35 formed in the transverse member I4. The bore. 33 extends completely through the piston rod 23 as shown in Fig. 2 and communicates with the feed cylinder bores at the forward sides of the feed pistons; the forward ends of the feed cylinder bores being connected by a transverse duct 35 formed in the head member I5. It will thus be seen that, when the pressure fluid is supplied through forward feed passage 28 and the reverse feed passage 29 is connected to exhaust; the rock drill is fed forwardly along the feed cylinders I0 and I I while, when pressure .fluid is supplied to the reverse feed passage 29 and the forward feed passage 28 is connected to the exhaust, the rock drill is fed rearwardly along the feed cylinders. The structure of the feeding mechanism, as previously mentioned, is substantially the same as that described in the patent mentioned above, and therefore a more detailed description of the feeding mechanism and the manner of mounting the rock drill thereon is not considered necessary.

Now referring to the improved feed regulating means, shown in Figs. 5 to 20 inclusive, and more particularly to Fig. 5, ,it will be observed that pressure fluid flows from a suitable source of supply through the inlet connection 4 into a bore 31 formed centrally in a throttle valve 38 rotatably mounted in the rear head 5 ofthe rock drill. This throttle valve is provided with a usual controlling handle 39 and the Wall thereof is traversed 5 by a radial passage 49 (see also Fig. 12) con- A necting the bore 31 with a circumferentially extending groove 4I cn the exterior valve periphery. Also formed on the exterior valve periphery in the same transverse plane as the groove 4I as shown 10 in Figs. 7 and 12is a circumferentially extending groove 42. Formed on the exterior periphery of the valve as shown in Figs. 6 and 11 are circumferentially extending grooves 43 and 44, the former being communicable Withran axial bore 45 15 in the valve through a radial passage 45. Arg. ranged transversely of the rear head 6 of the rock` drill is a bore 41 having mounted therein a rotary feed control valve 48, herein arranged parallel, with the throttle valve 38 and provided with a 20 suitable manual operating handle 49. The valve 8 is held in the bore 41and its rotative movement limited by a usual pin and'r slot connection 50. Connecting the throttle valve bore with the bore` 4i of the feed control valve and lying in the planes 25 v of the grooves 4I, 42 and 43, 44 are parallel passages 5I and 52, respectively, while lying in the same planes as these passages and grooves, as shown, in Figs. 6 and '7, are exhaust ports 53 and 54, respectively (see also Figs. 1l and 12). The passages 5I and 52 are connectible through thev feed control valve 48 with passages 55 and56, respectively, in turn communicable with the passages 29 and 28, respectively. As shown, the feed control valve 48 is traversed by a passage 51 and 35 a communicating right angle passage 5l2L which, when the valve is inthe position shown in Figs. 6 and i3, connects the passage 52 with the passage 55. The valve 48 also is traversed by a pas-` sage 58 which is communicable with an axial pas- 40 sage 59, which is in turn communicable through a radial passage 5U with the passage 5I, and a radial passage 6I with the passage 55 as shown in Figs. 5 and 13. As shown in Fig. 8, arranged parallel with the valve bore 41 is a passage 52 which 45 is communicable, when the valve 48 is in the position shown in Figs. 6 and l5, through a passage 63 with the passage 51 in the valve. When the valve is in the position shown in Figs. 8 and l5, the passage 52 is connected through a passage 64 50 and the transverse passage 58 in the valve 48 with a vent port 65. The valve 43 is also traversed by a radial passage 65 communicating with the axial passage 59 and when the valve is in the position y shown in Figs. 8 and l5, connects the passage 55 59 to exhaust through the vent port S3. The valve 48 is also provided with a longitudinal groove 54u (see Fig. 19) on its exterior periphery and this groove is communicable with the passages 52 and 58. Also formed on the valve 48 is a longitudinal 60 groove 55a (see Fig. 17) communicable with the passages 51 and 65.

Arranged within the throttle valve 38 is the improved automatic regulating valve for conv trolling the feeding pressure. This regulating 60 valve comprises a valve 91, herein of the ball type, arranged in the axial bore i5 and maintained on a valve seat 58 by a coil spring 59. The tension of the coil spring 59 may be adjusted by a slidable plunger 19 acting on the spring and arranged in 0 the bore 45 and adjustable by a set screw 1I threadedly connected at 12 within the throttle valve handle 39 as shown in Fig. 5. A1 axial passage 13 connects the valve bore 31 with the 5 bore 45, It Will thus be seen that irrespective of 7 the pressure within the valve bore 31, the pressure flowing through passage 52 to the forward feed passage 29 may be reduced by the valve 61 thereby maintaining, upon proper adjustment of the tension of spring S, the forward pressure at the desired degree irrespective of the pressure in the line. The set screw 'H is offset from the plunger 'lil so that when the set screw is removed the plunger abuts the end of the bore thereby to prevent escape of the plunger spring from the bore.

From the foregoing description, it will be evident that, when the throttle valve 38 and feed control valve 4B are in the position shown in Fig. 5, pressure uid may flow through the inlet conneet-ion 4, through the valve bore 3l, the axial passage i3, past the valve 91 (the latter being set to obtain the desired feeding pressure), through radial passage 4S, passage 52, passage 5l in the valve 48, passages 63, and the forward feed passage 28 which communicate with the feed cylinder bores at the rear sides of the feed pistons. At the same time the forward ends of the feed cylinder bores are connected to exhaust through the reverse feed passage 29, passages 55, 6l, 59, 5B and 5I, groove 42 and exhaust passage 53, and as a result, the rock drill is fed forwardly along the feed cylinders while, when the throttle valve is rotated into its reverse feeding position, pressure fluid may then flow through radial passage 49, groove 4I, passages 5l, B0, 59, 6| and 55 to the reverse feed passage 29 which communicates with the feed cylinder bores at the forward sides of the feed pistons, while the feed cylinder bores at the rear sides of the pistons are simultaneously connected to exhaust through passages 28 and 56 and groove fill on the throttle valve communicating with exhaust passage 54, and as a result the rock drill is fed rearwardly along the feed cylinders. The forward feed passage 28 may be connected to exhaust at will during the forward feeding operation simply by rotating the feed control valve 48 to the position shown in Fig. 8, thereby connecting the passage 55 to exhaust through passages 52, 54, 58 and E55. When the valve is in this position, the flow of pressure uid to the passage 23 is out off by the valve 4S. If it is desired to connect the reverse passage 29 to atmosphere during the reverse feeding operation, the valve 4S may be turned to connect the passage 55 with the passage 55, bore passage 53 and vent port 55, as shown in Fig. 15. At this time the communication between the supply passage 5l and passage 55 is cut off by the valve 48. Under certain conditions, for instance during the spotting operation when drilling down-holes, it is desirable to relieve the drill steel of the weight of the drill, and to accomplish this function, the feed control valve 48 is turned to the position shown in Figs. 9 and 10. At this time pressure fluid hows from passage 52 through the groove E@ on the valve 48, passage 58, axial passage 59, radial port 5! and passage 55 communicating with the reverse feed passage 29. Simultaneously the forward feed is connected to exhaust through passage 25, passage 55, passage 55, passage 5l in the valve 48, groove 55a and vent port 55. it will thus be seen that pressure may now at this time to the forward ends of the feed cylinders, under the control of throttle valve 33 to counteract the weight of the drill.

Now referring more specifically to the detail sectional views shown in Figs. 1l and 12, it will be noted that in the neutral or off position of the throttle valve 3B the supply of pressure iiuid to the passages 5! and 52 communicating with the reverse and forward feed passages is cut off. In the forward feed position, as shown in Fig. 11,

the pressure iuid is supplied through the pas-v sages 45, 45 and groove 43 in the throttle valve to the forward feed passage 52, while in Fig. 12 the reverse feed passage 5I is vented to atmosphere through the groove 42 on the throttle valve communicating with the vent port 53. When the throttle valve is in the reverse feed position shown in Fig. l2, pressure fluid is supplied through passage 43 and groove 4| in the throttle valve to the reverse feed passage 5l, while the forward feed passage 52 is out off by the throttle valve and the passage 55 is vented to atmosphere through the groove 44 on the valve communicating with the vent port 55, as shown in the reverse feed position in Fig. 11. It will thus be seen that pressure fluid may be supplied to either the reverse feed passage 5l or the forward feed passage 52 and that the passages 5I and 52 may both be connected to exhaust, it being possible to adjust the throttle valve to effect either forward or reverse feed.

The auxiliary feed control valve 48 may be adjustedeintopositions to effect reversal of the feed irrespective of the position of the throttle valve 38 or the direction of feed and may also be adiusted to vary the rate of feed in either direction and to control the feeding pressure during the "spotting operation. When the auxiliary feed control valve is in its forward feed position, as shown in Fig. 13, i. e. the position corresponding to that shown in Fig. 5, pressure fluid may flow through the forward feed passage52 through the passa es 5l@ and 51, groove 65a on the valve, pas'- sage 53 and passage 55 communicating with the forward feed passage 28. `At that same time the reverse feed passage 29 is connected to exhaust through passage 55, passage 6l in the valve, the bore 59, passage 5), the reve-rse feed passage 5I and groove 42 o-n the throttle valve communicating with the vent passage 53. When it is desired to effect reversal of the feed the auxiliary valve 48 is rotated through 189 from the position shown in Fig. 13 to the position shown in Fig. 14 (the latter being the reverse feed position corresponding to Fig. 9). Pressure fluid then iiows through the throttle valve, through the y supply passage 52, groove 54a in the valve 45, passage 58, bore 59, passage 6l and passage 55 communicating with the reverse feed passage 29. At that time the forward feed passage 28 is connected to exhaust through passage 55, passage 53, passage 5l, groove S5a and vent passage 55.

If it is desired to connect the reverse feed passage 29 to atmosphere during the feeding operation for instance to discontinue the forward feed,

the auxiliary control valve 4B may be turned through 45 from the position shown in Fig. 13 to the position shown in Fig. 15 (the position corresponding to that shown in Fig. 8), and at that time the passage 55 communicating with the reverse feed passage 29 is connected through passage 65, bore 59 and passage 58 to the vent port 55. The fluid supply and exhaust passages may be entirely cut off when the auxiliary valve is moved into its neutral or off position shown in Fig. 16.

The various passages in the auxiliary feed control valve 48 through which uid fio-ws to the feed supply and emaust passages are clearly shown in Figs. 17, 18, 19 and 20 which. shows the auxiliary valve in its different positions, these views showing most clearly the grooves 64e and 65a.

In order to maintain substantially the same constant feeding force on the feed pistons 29, 2| and the same forward feeding pressure on the drill steel 3 When drilling downwardly as when drilling horizontally or upwardly, the tension of the spring E8 acting on the automatic regulating valve 8l is adjusted by the set screw During down-hole drilling, the normal pressure plus the weight o-f the drill may create an excessive feeding force so as to prevent proper rotation of the drill steel and in order to reduce the feeding pressure, the tension of the spring 98 is increased. During up-hole drilling, the feeding pressure may be increased by reducing the tension of the spring 8S.

In the form of the invention shown in Figs. 21 to 32 inclusive, the automatic feed regulating valve is arranged in axial alinement with the feed control valve as shown in Fig. 2l. In this construction the pressure fluid flows from a suitable source of supply through the inlet connection 4 to a central bore 'I5 formed in the throttle valve '|S. Communicable with the bore 'l5 is a reduced axial bore 19 and communicating with this bore are radial ports 89 and 8|, the former communicating with a circumferentially extending groove 82, while the latter communicates with a circumferentially extending groove 83. Formed on the exterior periphery of the throttle valve in the same transverse plane as the grooves 82, 83 are circumferentially extending grooves 88 and 85, respectively connected by a longitudinal groove 89. Arranged in a bore 8l formed in the rear head S of the rock drill is a rotary feed control valve 88 arranged parallel with the throttle valve. Arranged in the same planes as the grooves and passages 8|, 83, 85 and 89, 82, 84 are parallel passages 99 and 89 respectively, communicating with the valve bore 8l. These passages 89 and 99 are communicable, under the control of the valve 88 and an automatic regulating valve 9|, With passages 92 and 93 respectively, in turn communicating with the forward and reverse feed passages 28 and 29 respectively. The passage 89 is also communicable with the passage 28, under the control of the valve 88, through a passage 94. Communicable with the grooves 84, and 85 in the throttle valve '|8 and controlled by the throttle valve 'I8 is an exhaust port (see Figs. 22 and 24). Communicable With the passage 94 is a passage 96 (see Figs. 23, 25 and 28).

Formed in the feed control valve 88 is a radial passage 91 disposed in the plane of passage 89 and communicating with an axial passage 98. Also communicating with the axial passage 98 is a radial vent passage 99 communicable With an exhaust passage-|99 in the head 6. Formed in the plane of the passage 91 is a circumferen- `tially extending groove communicable with the passage 89. Also formed in the valve 88 is a radial passage |92 communicating with a right angled radial passage |93, both disposed in the plane of the passage 99. The passage |93 communicates with a longitudinal groove |94 on the valve 88. Formed in the head 6 in the planes of passages 99 and 99 are passages |95 and |96 respectively connected by a passage |91. Communicable with the passages |02, |93 in the valve 88 lis a vent passage |98.

The automatic regulating valve 9| herein comprises a ball valve |99 held on its seat ||9 by a coil spring I I arranged in a bore I I2 alined with the bore 8l. Connecting bore 8l with bore ||2 is an axial passage |I3. The tension of spring is adjustable by a follower screw I I4. 'I'he function of this regulating valve is identical to that in the form of the invention described above.

When the throttle valve 28 and the feed control 5 valve 88 are in the position shown in Figs. 21, 22,

23 and 26, i. e. during normal running of the drill, pressure fluid may flow through the inlet connection 4, bore l5 in the valve i8, axial passage '|9, passages 89, 99, 97|, 98 and IIB, past the auto- 10 matic regulating valve 9| (which is set to obtain the desired feeding pressure) and through bore I I2 and passage 92 communicating with the forward feed passage 28, while the reverse feed passage 29 is simultaneously connected to exhaust 15 (see Fig. 22) through passages 93 and 95, passages 98, |92 in the valve 88, passage 99, groove 85 in the throttle valve 'F8 and exhaust passage 95, and as a result, forward feed of the rock drill is effected. When the throttle valve 'i8 is rotated 20 into the position shown in Figs. 24 and 25, pressure fluid may ow through the bore l5 in the throttle valve, through axial passage |9 and passages 8|, 99, passages |92, |98 in the valve 88, passages |95 and 93 communicating with the reverse feed pas- 25 sage 29, while the forward feed passage 28 is simultaneously connected to exhaust through passage 9d, passage 99, grooves 84, 85 and 88 in the throttle valve and vent passage 95, and as a result,

reverse feed is effected. When the feed control 30 valve 88 is turned in a clockwise direction through 90 from the position shown in Figs. 21, 22 and 23 (as shown in Figs. 30, 3l and 32) the flow of pressure fluid through either of the passages 89, 99 to the forward and reverse feed passages 28 and 29 35 is cut olf by the valve 88 and both the forward and reverse feed passages 28 and 29 are connected to exhaust through the vent passage |98, the passages 93 and 94 being connected to exhaust through groove |94 in the valve 88 and passages 40 |95, |93 and |92 communicating with the vent passage |98. If it is desired to supply fluid to the reverse feed during down-hole drilling to relieve the drill steel of the weight of the drill during the spotting of a hole, the valve 88 is turned in a 45 clockwise direction through from the position shown in Figs. 2l, 22, 23 and 26 (as shown in Figs. 27, 28 and 29). At this time, pressure fluid flows through passage B9, groove I9| in the valve 88, passages |99, |91 and through passage 93 50 communicating with the reverse feed passage 29, while the forward feed passage 28 is connected to exhaust through passages 97, 98 and 99 in the valve 88 communicating with the vent passage |99. As the general mode of operation of the 55 rock -drill disclosed herein is well understood by those skilled in the art and as the operation of the control mechanism has been clearly described above, further description of the operation of the improved drill is unnecessary. 60 As a result of this invention it will be noted that improved regulating meansare provided for a rock drill feeding mechanism whereby the forward and reverse feeds may be controlled at Will and the feeding pressure may be automatically 65 regulated. It will further be noted that by providing an auxiliary feed control valve, the feeding pressure may be controlled at will independently of the throttle valve, and it will still further be evident that improved pneumatic feeding 70 mechanism is provided for a drifter type rock drill wherein an extremely sensitive feed may be attaine-d irrespective of whether the drill is operating to drill up-holes, down-holes or holes in any desired intermediate positions. These and 75 other uses and advantages of the improved feeding mechanism will be clearly apparent to those skilled in the art.

While there is in this application specifically described two forms which the invention may assume in practice, it will be understood that these forms of the saine are shown for purposes of illustration and that the invention may be modifie-d and embodied in various other forms without departing from its spirit or the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent is:

1. In a drill feeding mechanism, the combination with a reversible pressure fluid actuated feeding motor, of controlling means for said motor including a throttle valve for controlling the supply and exhaust of actuating iiuid to said feeding motor and movable into dierent controlling positions to effect operation of said motor in either direction, and an auxiliary manual controlling valve operable at will for interrupting the supply of fluid to said feeding motor independently of said throttle valve.

2. In a drill feeding mechanism, the combination with a reversible pressure fluid actuated feeding motor, of controlling means for said motor including a throttle valve for controlling the supply and exhaust of actuating fluid to said feeding motor and movable into different controlling positions to effect operation of said motor in either direction, and an auxiliary manual controlling valve operable at will for interrupting the supply of fluid to said feeding motor independently of said throttle valve and for connecting the motor passage previously supplied with actuating fluid with the exhaust.

3. In a drill feeding mechanism, the combination with a reversible pressure fluid actuated feeding motor, of means for supplying fluid to and exhausting fluid from said feeding motor including a forward feed passage and a reverse feed passage, a throttle Valve for controlling fluid flow through said passages to effect feed in either direction, and an auxiliary manual controlling valve operable at will for regulating fluid now through said passages independently of said throttle valve and irrespective of the direction of speed.

4. In a drill feeding mechanism, the combination with a reversible pressure uid actuated feeding motor, of means for supplying fluid to and exhausting fluid from said feeding motor including a forward feed passage and a reverse feed passage, a throttle Valve for controlling fluid flow through said passages, and an auxiliary manual controlling valve operable at will for connecting either passage with the exhaust independently of said throttle valve.

5. In a drill feeding mechanism, the combinae tion with a reversible pressure uid actuated Vfeeding motor, of means for supplying fluid to and exhausting uid from said feeding motor including a forward feed passage and a reverse feed passage, a throttle valve for connecting either passage with the supply and exhaust to effect operation of said motor in either direction, and an auxiliary manual controlling valve operable at will for interrupting uuid flow through the passages independently of said throttle valve.

6. In a drill feeding mechanism, the combination with a reversible pressure fluid actuated feeding motor, of means for supplying fluid to and exhausting fluid from said feeding motor including a forward feed passage and a reverse j feed passage, a throttle valve for connecting either passagev with the supply and the other to exhaust to effect operation of said motor in either direction, and an auxiliary manual controlling valve operable at will for connecting either passage with the exhaust independently 5 of said throttle Valve.

7. In a drill feeding mechanism, the combination with a pressure fluid actuated feeding motor, of controlling means for said motor including a manually operable throttle valve element having an internal chamber, and automatic means for regulating the feeding pressure including an automatic regulating valve arranged within the chamber in said throttle valve element, said controlling means including a passage controlled by said throttle valve element for supplying pressure fluid to said feeding motor, said regulating valve being openable by line pressure and the pressure fluid flowing past said regulating valve to said feed passage, said automatic valve being cut off from said feed passage when the latter is closed by said throttle valve element, said throttle valve element being arranged between said automatic valve and said feed passage.

8. In a drill feeding mechanism, the combination with a pressure fluid actuated feeding motor, of controlling means for said motor including a manually operable throttle valve element having an internal chamber, and automatic means for regulating the feeding pressure including an automatic regulating valve arranged within the chamber in said throttle valve element, said controlling means including a passage controlled by said throttle valve element for supplying pressure fluid to said feeding motor, said regulating valve being openable by line pressure and the pressure fluid flowing past said regulating valve to said feed passage, said automatic valve being cut off from said feed passage when the latter is closed by said throttle Valve element, said throttle valve element being arranged between said automatic valve and said feed passage, and said automatic regulating means including a valve seat with which said automatic regulating valve is engageable, a spring for yieldably urging said regulating valve toward saidv seat, and an adjustable device carried by said throttle valve element for adjusting the tension of said spring.

9. In a drill feeding mechanism, the combination with a reversible pressure fluid actuated feeding motor, of controlling means for said motor including a throttle valve for controlling the supply of actuating fluid to and exhaust from said motor, an auxiliary runner-controllable valve operable at will for interrupting the supply of fluid to said feeding motor independently of said throttle valve, and an automatic regulating Valve for automatically controlling the fluid supply to said feeding motor and arranged in the fluid flow path between-the throttle valve and the source of fluid supply.

10. In a drill feeding mechanism, the combination with a reversible pressure fluid actuated feeding motor, of means for supplying fluid to and exhausting fluid from said feeding motor in# cluding a forward feed passage and a reverse feed passage, a throttle valve for controlling said passages, and an automatic regulating valve for controlling the supply of fluid through said forward feed passage and arranged between said throttle valve and the feeding motor, said throttle valve being controllable to render said auto` matic controlling'means inoperative at will.

11. In a drill feeding mechanism, the combina-v tion with a reversible pressure fluid actuated. 75

feeding motor, of means for supplying fluid 'to and exhausting uid from said feeding motor including a forward feed passage and a reverse feed passage, a throttle valve for controlling said passages and adjustable to effect feed in either direction, an auxiliary runner-controllable valve operable at will for controlling said passages independently of said throttle Valve, and' an automatic regulating valve for controlling the flow of actuating iiuid to said forward feed passage.

12. In a drill feeding mechanism, the combination with a reversible pressure fluid actuated feeding motor, of means for supplying fluid to and exhausting fluid from said feeding motor including a forward feed passage and a reverse feed passage, a throttle valve for controlling said passages and adjustable to elfect feed in either direction, an auxiliary runner-controllable valve operable at will for controlling said passages independently of said throttle valve, and an automatic regulating valve for controlling the ow of actuating fluid to said forward feed passage and arranged between said throttle Valve and said auxiliary valve.

13. In a drill feeding mechanism, the combination with a pressure fluid actuated feeding motor, of automatic pressure reducing means for regulating the pressure within said feeding motor comprising means forming a valve seat, a valve, a coil spring for urging said valve toward said seat, removable means for adjusting the tension of said spring, and means for preventing escape of said spring when said adjusting means is removed.

14. In a drill feeding mechanism, the combination with a pressure fluid actuated feeding motor, of controlling means for said motor including a throttle valve element having an internal chamber, and passages controlled thereby for supplying fluid to and exhausting fluid from said motor, and an automatic regulating valve for controlling the flow of pressure fluid through said supply passage in said valve element, said regulating valve being arranged within the chamber in said throttle valve element, said throttle valve element arranged between said regulating valve and said supply passage and movable into a position to cut off said regulating valve from said supply passage when the latter is closed by said throttle valve element.

15. In a drill feeding mechanism, the combination with a pressure fluid actuated feeding motor, of controlling means for said motor including a throttle valve element having an internal chamber, and passages controlled thereby for supplying fluid to ,an exhausting fluid from said motor, and an automatic regulating valve for controlling the flow of pressure fluid through said supply passage in said valve element, said regulating valve being arranged within the charnber in saidithrottle valve element, said throttle valve element arranged between said regulating valve and said supply passage and movable into a position to cut off said regulating valve from said supply passage when the latter is closed by said throttle valve element, said regulating valve including means forming a valve seat, a valve element, a spring urging said valve element toward said seat, and means for adjusting the tension of said spring, the fluid flowing past said regulating valve element and said throttle valve to said supply passage.

16. In a drill feeding mechanism, the combination with a pressure uid actuated feeding motor,

rof controlling means for said motor including a throttle valve for controlling the supply of actuating fluid to and the exhaust from said feeding motor, said throttle valve being adjustable into different controlling positions to effect operation of said feeding motor in either direction, and an auxiliary manual controlling valve operable at will independently of said throttle valve and irrespective of the adjusted position of the latter for interrupting the supply of fluidto said feeding motor independently of said throttle valve.

17. In a drill feeding mechanism, the combination with a pressure fluid actuated feeding motor, of controlling means for said motor including a throttle valve for controlling the supply of actuating fluid to and the exhaust from said feeding motor, said throttle valve being adjustable into different controlling positions to effect operation of said feeding motor in either direction, and an auxiliary manual controlling valve operable at will independently of said throttle valve and irrespective of the adjusted position of the latter for interrupting the supply of fluid to said feeding motor and for connecting the motor supply passage with the exhaust.

18. In a drill feeding mechanism, the combination with a pressure fluid actuated feeding motor, of controlling means for said motor including a throttle valve for controlling the supply of actuating fluid to and the exhaust from said feeding motor, said throttle valve being adjustable into different controlling positions to effect operation 4of said feeding motor in either direction, and an auxiliary manual controlling Valve operable at will independently of said throttle valve and irrespective of the adjusted position of the latter for interrupting the supply of fluid to said feeding motor and for connecting the motor passage previously Suppued with actuating uuid with the exhaust, said auxiliary valve having passage means through which the supply of fluid to said motor flows.

19. In a drill feeding mechanism, the combination with a drill and a feeding motor for said drill, of feed control means carried by said drill for controlling the supply of fluid to and the eX- haust of uid from said feeding motor, an auxiliary valve for controlling said supply and exhaust and operable independently of said throttle valve, and an automatic regulating valve for controlling said fluid supply to regulate automatically the feeding pressure, said valve being openable by line pressure and arranged in the fluid flow path between the source of fluid supply and said feed control means.

2G. In a drill feeding mechanism, the combination with a drill and a feeding motor for said drill of feed control means carried by said drill for controlling the supply of fluid to and the exhaust of fluid from said feeding motor, an auxiliary valve for controlling said supply and exhaust and operable under the control of and at the will of the operator independently of'said throttle valve, and an automatic regulating valve for controlling said fluid supply to regulate automatically the feeding pressure.

21. In a drill feeding mechanism, in combination, a pressure fluid actuated feeding motor of the reversible type, and controlling means for said motor including valve means positionable to supply a reduced feeding pressure to said motor to effect forward feed while venting the opposite end of said motor, to supply full feeding pressure to said feeding motor to effect retraction while venting the then opposite end of said motor, and auxiliary means operable at the will of a LlO drill runner to effect venting of both ends of said feeding motor irrespective of which end is connected by said first mentioned means with fluid supply.

22, In a drill feeding mechanism, in combination, a pressure fluid actuated feeding motor of the reversible type, and controlling means for said motor including valve means positionable to supply a reduced feeding pressure to said motor to effect forward feed while venting the opposite end of said motor, to supply full feeding pressure to said feeding motor to effect retraction while venting the then opposite end of said motor, and auxiliary means operable at the will of a drill runner to effect venting of both ends of said feeding motor irrespective of which end is connected by said first mentioned means with fluid supply and also operable to supply reduced pressure to effect retraction.

23. In a drill feeding mechanism, the combination with a drill and a reversible feeding motor for said drill, of feed control means carried by the drill for controlling the supply of uid to and the exhaust of fluid from said feeding motor and adjustable into different controlling positions to effect feed in either direction, an auxiliary valve for controlling said supply and exhaust for effecting reversal of said feeding motor and operable independently of said throttle valve, and an automatic regulating valve for controlling said fluid supply to regulate automatically the feeding pressure.

24. In a drill feeding mechanism, the combination with a drill and a reversible feeding motor for said drill, of feed control means carried by said drill for controlling the supply of fluid to and the exhaust of fluid from said feeding motor and adjustable into different controlling positions to effect operation of said feeding motor in either direction, an auxiliary feed and reversing valve for controlling said supply and exhaust and operable under the control of and at the will of the operator independently of said throttle valve, and an automatic regulating valve for controlling said fluid supply to regulate automatically the feeding pressure.

25. In a drill feeding mechanism, in combination, a pressure fluid actuated feeding motor of the reversible type, and controlling means for said motor including valve means positionalole to supply a reduced feeding pressure to said motor to effect forward feed while venting the cpposite end of said motor, to supply full feeding pressure to said feeding motor to effect retrac- Y tien while venting the then opposite end of said motor, and auxiliary means operable at the will of a drill runner to effect venting of both ends of said feeding motor irrespective of which end is connected by said rst mentioned means with fluid supply.

26. In a drill feeding mechanism, the combination with a reversible pressure iiuid actuated feeding motor, of controlling means for said motor including a throttle valve for controlling the supply of actuating fluid to and exhaust from said motor, an auxiliary runner-controllable valve operable at will for interrupting the supply of fluid to said feeding motor independently o-f said throttle valve, and an automatic regulating valve for automatically controlling the fluid supply to said feeding motor and arranged between the feeding motor and said auxiliary valve.

27. In a drill feeding mechanism, the combination with a reversible pressure fluid actuated feeding motor, of means for supplying fluid to and exhausting liuid from said feeding motor including a forward feed passage and a reverse feed passage, a throttle valve for controlling said passages, and an automatic regulating valve for controlling the supply of fluid through said forward feed passage and arranged between said throttle valve and the feeding motor, said throttle valve being controllable to render said automatic controlling means inoperative at will and adjustable to supply pressure fluid to said feeding motor when said auto-matic controlling means is inoperative.

28. In a drill feeding mechanism, the combination with a reversible pressure fluid actuated feeding motor, of means for supplying fluid to and exhausting uid from said feeding motor including a forward feed passage and a reverse feed passage, a throttle. valve for controlling said passages, an auxiliary runner-controllable valve operable at will for controlling said passages independently of said throttle valve, and an automatic regulating valve for controlling the flow of actuating fluid to said forward feed passage, said automatic Valve being arranged in the fluid supply passage between the source of fluid supply and said throttle valve,

29. In a drill feeding mechanism, the combination with a reversible pressure nuid actuated feeding motor, of means for supplying fluid to and exhausting fluid from said feeding motor including a forward feed passage and a reverse feed passage, a throttle valve for controlling said passages, an auxiliary runner-controllable valve operable at will for controlling said passages independently of said throttle Valve, and an automatic regulating valve for controlling the flo-w of actuating fluid to said forward feed passage Y and arranged between said throttle valve and said feeding motor, said throttle Valve being adjustable to supply pressure fluid to said feeding motor when the fluid supply to said automatic regulating Valve is cut off.

30. In a drill feeding mechanism, a reversible feeding motor, a throttle valve for controlling the feeding pressure and adjustable to effect feed in either of opposite directions, and an auxiliary feed reversing valve'for effecting feed reversal irrespective of the position of said throttle valve.

3l. In a drill feeding mechanism, areversible feeding motor, a throttle valve for controlling the feeding pressure and adjustable to effect feed in either of opposite directions, and an auxiliary feed reversing Valve for effecting feed reversal irrespective of the position of said throttle valve, said auxiliary valve also being adjustable to vary the rate of feed in either direction. Y

32. In a drill feeding mechanism, a reversible feeding motor and controlling means for said motor including a throttle valve, passages controlled by said throttle valve for conducting pressure fluid to and exhausting fluid from said motor, said throttle Valve being adjustable into different controlling positions, in one position for effecting feed" in one direction and in another position for effecting feed in the reverse direction, and an auxiliary feed controlling valve adjustable to effect reversal of the feeding motor irrespective of the adjusted position of said throttle valve.

33. In a drill feeding mechanism, a reversible feeding motor and controlling means for said motor including a throttle valve, passages controlled by said throttle valve for conducting pressure uid to and exhausting liuid from said motor,` said throttle valve being adjustable into different controlling positions, in one position for effecting feed in one direction and in another position for effecting feed in the reverse direction, and an auxiliary feed controlling valve adjustable to effect reversal of the feeding motor irrespective of the adjusted position of said throttle valve and controllable to vary the feeding pressure irrespective of the direction of feed.

34. In a drill feeding mechanism, a reversible feeding motor and controlling means for said motor including a throttle valve, fluid supply and exhaust passages controlled by said throttle valve for supplying fluid to and exhausting fluid from said feeding motor, and an auxiliary feed controlling and reversing valve having passage means for connecting either of said passages to the supply and either of said passages with the exhaust to effect operation of said feeding motor in reverse directions.

35. In a drill feeding mechanism, a reversible feeding motor and controlling means for said motor including a throttle valve, fluid supply and exhaust passages controlled by said throttle valve for supplying fluid to and exhausting fluid from said feeding motor, and an auxiliary feed controlling and reversing valve having passage means for connecting either of said passages to the supply and either of said passages with the exhaust to effect operation of said feeding motor in reverse directions and operable to effect feed reversal irrespective of the position of said throttle valve and the direction of feed.

36, In a drill feeding mechanism, a reversible feeding motor and controlling means for said motor including a throttle valve, passages constituting in one position of said throttle valve respectively a fluid supply passage and an exhaust passage, said passages being controlled by said throttle valve, an auxiliary feed control valve, and passages controlled by said auxiliary valve for supplying pressure fluid to and exhausting fluid from said feeding motor, said auxiliary valve being adjustable to connect either of said last mentioned passages with either of said first mentioned passages.

37. In a drill feeding mechanism, a reversible feeding motor and controlling means for said motor including a throttle valve, passages constituting in one position of said throttle valve respectively a fluid supply passage and an exhaust passage, said passages being controlled by said throttle valve, an auxiliary feed control valve, and passages controlled by said auxiliary valve for supplying pressure fluid to and exhausting j fluid from said feeding motor, said auxiliary valve being adjustable to connect either of said last mentioned passages with either of said first mentioned passages and said throttle valve being adjustable to connect either of said first mentioned passages with the source of fluid supply and either of said first mentioned passages with the exhaust.

38. In a drill feeding mechanism, the combination With a reversible pressure fluid actuated feeding motor, of controlling means for said motor including a valve, passages controlled by said valve for supplying pressure fluid to said feeding motor to effect operation thereof in either of opposite directions, said valve being positionable to connect either of said passages with a source of fluid supply and the other with exhaust, supplemental passages, and an auxiliary control valve for controlling said supplemental passages and positionable to connect either of said supplemental passages with either of said first mentioned passages to effect feed reversal and for controlling said supplemental passages to regulate the rate of feed.

39. In a drill feeding mechanism, the combination with a reversible pressure fluid actuated feeding motor, of controlling means for said motor including a valve, passages controlled by said valve for supplying pressure fluid to said feeding motor to effect operation thereof in either of opposite directions, said valve being positionable 10 to connect either of said passages with a source of fluid supply and the other with exhaust, supplemental passages, and an auxiliary control valve for controlling said supplemental passages and positionablev to connect either of said supplemental passages with either of said first mentioned passages to effect feed reversal and for controlling said supplemental passages to regulate the rate of feed, said auxiliary valve having crossed passages communicable with either of said passages.

40. In a drill feeding mechanism, the combination With a reversible pressure fluid actuated feeding motor, of controlling means for said motor including a manually operable throttle valve for controlling the supply of pressure fluid to the feeding motor to effect operation thereof in either of opposite directions, and automatic means for regulating the feeding pressure during feeding of said motor in one direction including an automatic feed controlling valve arranged within said throttle valve and openable by line pressure for controlling the ilovv of pressure fluid throughl said throttle valve to the feeding motor, said throttle valve being adjustable to cut off said automatic controlling valve to interrupt feed in one direction and to effect feed in the opposite direction independently of said automatic valve.

lll. In a drill feeding mechanism, the combination with a reversible pressure uid actuated feeding motor, of controlling means for said motor including a manually operable throttle valve for controlling the supply of pressure fluid to said motor to effect operation thereof in either of opposite directions, and automatic means for regulating the feeding pressure during operation of said feeding motor in one direction including an automatic controlling valve arranged Within said throttle valve, said automatic regulating means including a valve seat formed Within said throttle valve, a valve, a spring for yieldably urging said valve toward said seat, and an adjustable device carried by said throttle valve forV adjusting the tension of said spring, said automatic valve being openable by line pressure and controlling flow of pressure fluid through said throttle valve to said feeding motor, said throttle valve being positionable to cut off said automatic regulating means to interrupt operation of said feeding motor in one direction and to effect operation of said feeding motor in the reverse direction independently of said automatic regulating means.

42. In a drill feeding mechanism, the combination With a pressure fluid actuated feeding motor, of controlling means for said motor including a throttle valve and passages controlled thereby for supplying fluid to and exhausting fluid from said motor, said throttle valve having a passage for conducting pressure fluid to said supply passage and a passage for venting said exhaust passage, and an automatic regulating valve for controlling the flow of pressure fluid from said supply passage in said throttle valve, said regulating valve being arranged Within said throttle valve and said throttle valve being positionable to cut oif said regulating valve to interrupt fluid flow through said supply passage and to connect said exhaust passage with the supply.

43. In a drill feeding mechanism, the combination with a pressure fluid actuated feeding motor, of controlling means for said motor including a throttle valve and passages controlled thereby for supplying fluid to and exhausting fluid from said motor, said throttle valve having a passage for conducting pressure fluid to said supply passage and a passage for venting said exhaust passage, and an automatic regulating valve for controlling the flow of pressure fluid from said supply passage in said throttle valve, said regulating valve being arranged within said throttle valve and including means forming a valve seat within said throttle valve, a valve, a spring urging said valve towards its seat, and means carried by said throttle valve for adjusting said tension of said spring, said throttle valve being positionable to cut off said regulating valve to interrupt fluid flow through said supply passage and to connect said exhaust passage with the supply.

44. In a drill feeding mechanism, the combination with a reversible pressure fluid actuated feeding motor, of controlling means for said motor including a throttle valve for controlling the supply of actuating fluid to and exhaust from said motor and adjustable to effect feed in either of opposite directions, an auxiliary runner-controllable valve operable at will for interrupting the supply of fluid to said feeding motor independently of -said throttle valve and operable to effect feed reversal when said throttle valve is in forward feeding position, and an automatic regulating valve for automatically controlling the fluid supply to said feeding motor and arranged in the fluid flow Apath between said throttle valve and the source of uid supply.

45. In a drill feeding mechanism, the combination with a reversible pressure fluid actuated feeding motor, of means for supplying fluid to and exhausting fluid from said feeding motor including a forward feed passage and a reverse feed passage, a throttle valve for controlling said passages and adjustable to effect feed in either of opposite directions, and an automatic regulating valve for controlling the supply of fluid through said forward feed passage and arranged between said throttle valve and the feeding motor, said throttle valve being adjustable to cut off the fluid supply to said automatic valve to interrupt the forward feed and to supply pressure fluid to said reverse feed passage to effect feed reversal independently of said automatic valve.

46. In a drill feeding mechanism, the combination with a reversible pressure fluid actuated feeding motor, of means for supplying pressure fluid to and exhausting fluid from said feeding motor including a forward feed passage and a reverse feed passage, a throttle valve for controlling said passages and adjustable to effect feed in either of opposite directions, and an automatic regulating valve for controlling the supply of fluid through said forward feed passage and arranged between said throttle valve and the feeding moto-r, said throttle valve being controllable to render said automatic controlling means inoperative at will and to interrupt fluid flow to said forward feed passage and to supply pressure fluid to said reverse feed passage independently of said automatic valve.

47. In a drill feeding mechanism, the combination with a reversible pressure fluid actuated feeding motor, of means for supplying fluid to and exhausting fluid from said feeding motor including a forward feed passage and a reverse feed passage, a throttle valve for controlling said passages and adjustable to effect feed in either of opposite directions, an auxiliary runner-controllable valve operable at will for controlling said passages independently of said throttle valve and operable to effect feed reversal when said throttle valve is in forward feeding position, and an auto- 10 matic regulating valve for controlling the flow of actuating fluid to said forward feed passage, said throttle valve being positionable to cut off said automatic regulating valve while effecting feed reversal. 48. In a drill feeding mechanism, the combina-A tion with a reversible pressure fluid actuated feeding motor, of means for supplying pressure fluid to and exhausting fluid from said feeding motor including a forward feed passage and a reverse feed passage, a throttle valve for controlling said passages and adjustable to effect feed in either of opposite directions, an auxiliary runner-controllable valve operable at will for controlling said passages independently oflsaid throttle valve and operable to effect feed reversal when said throttle valve is in forward feed position, and an auxiliary regulating valve for controlling the flow of actuating fluid to said forward feed passage and arranged between said throttle valve and said auxiliary valve, said throttle valve being positionable to out off said automatic valve to interrupt flow of actuating fluid to said forward feed passage and to supply pressure iluid to said reverse feed passage independently of said automatic valve.

49. In a drill feeding mechanism, the combination with a drill, and a feeding motor for said drill, of feed controlling means carried by said drill for controlling the supply of fluid to and the exhaust of fluid from said feeding motor, a throttle valve for controlling said fluid supply and exhaust and adjustable to effect feed in either of opposite directions, an auxiliary valve for controlling said supply and exhaust and operable independently of said throttle valve, said auxiliary valve being positionable to effect feed reversal when said throttle valve is in forward feed position, and an automatic regulating valve for controlling the fluid supply to regulate automatically the feeding pressure, said valve being openable by line pressure and arranged in the fluid flow path between the source of fluid supply and said feed control means, said throttle valve being positionable to cut off said automatic valve to interrupt the forward feed supply to said feeding motor and to supply pressure fluid to effect reverse feed independently of said automatic valve.-

50. In a drill feeding mechanism, the combination with a drill and a feeding motor for said drill, of feed control means carried by said drillV for controlling supply of fluid to and the exhaust of fluid from said feeding motor and adjustableV toeffect feed in either of opposite directions, an y auxiliary valve for controlling the supply and exhaust and operable under the control of and at the will of the operator independently of said throttle valve and operative to effect feed reversal irrespective of the position of said throttle valve, and an automatic regulating valve for controlling said fluid supply to regulate automatically the feeding pressure.

MERvIN CHESTER` HUFFMAN.

*jf/pff!!! CERTiiCATE on enRREc'neN.

latent No. 2,015,678. ,Y @amber 1, i935.

MERVIN @nested Ruini/mi.

it is hereby eertitied that errer appears in the printed speeiiieatien of the above numbered patent requiring correction as follows: hie Z, first column, line 6G, strike out the semi-colon and insert e. minnie.; and second column, line 56, for "63" read 65; page 5, first column, line 48, for "speed" read feed; page 6, second column, iine 10, claim it, strike out the words "independently of said throttle vnlve"; line 57, claim Z0, after "drill" first oeeurrence, insert a comme; and page S, s ecnnd column, line 2l, claim 39, after "said" insert the word supplemental; and that the said Letters Patent should be read with theseeerrections therein that the same may conform te the reedrd oi the case in the Patent Oiiiee.

Signed and sealed this i9th day 0i November, A. D. 1935.

Leslie Frazer (Seal) Acting Commissioner oi Patents. 

